diff --git a/base16384.c b/base16384.c
index 69d318f..6819f1a 100644
--- a/base16384.c
+++ b/base16384.c
@@ -119,8 +119,8 @@ int main(int argc, char **argv){
         default: break;
     }
 
-    if(is_standard_io(INPUT)) fclose(fp);
-    if(is_standard_io(OUTPUT)) fclose(fpo);
+    if(!is_standard_io(INPUT)) fclose(fp);
+    if(!is_standard_io(OUTPUT)) fclose(fpo);
 
     return 0;
 }